Antibacterial Quiz Flashcards

1
Q

A 31 year old white intravenous drug user was admitted to the hospital with a four week history of cough and fever. A chest radiograph showed left upper lobe cavitary infiltrate. Culturres of sputum yielded M. tberculosis susceptible to all antimycobacterial drugs. The patient received isoniazid, rifampin, and pyrazinamide. The patient’s sputum remianded culture-positive for the subsequent four months. Which one of the following is the most likely cause of treatment failure?

A. False-positive cultures

B. Drug resistance

C. Noncompliance by the patient

D. Malabsorption of the medications

E. Concomitant infection with HIV

A

C. Noncompliance by the patient Unverified

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2
Q

A 45 year old man presents to the emergency department with severe pneumonia. He recently returned from a business trip, and has a history of smoking and alcohol abuse. An x-ray film shows extensive consolidation affecting portions of each lung lobe. Culture on charcoal yeast extract medium grows out a small gram-negative bacterium Legionella. Which of the following antibiotics is the most appropriate treatment for this patient?

A. Ceftriaxone

B. Chloramphenicol

C. Clindamycin

D. Erythromycin

E. Sufonamides

A

D. Erythromycin Unverfied

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3
Q

Your 23 year old female is pregnant and has gonorrhea. The medical history includes anaphylaxis following exposure to amoxicillin. Worried about compliance, you would like to treat patient with single does, so you choose

A. Cefixime

B. Ceftriaxone

C. Spectinomycin

D. Tetracycline

E. Ciprofloxacin

A

C. Spectinomycin

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4
Q

An 18-month- old boy is taken to the emergency department because he has a fever and is irritable and lethargic. The mother says the boy was fine when he went to bed the night before. In response to questioning about drug allergies, she says that the boy recently had a severe hypersensitivity reaction to amoxicillin. Neurologic examination shows the obtunded infant to have marked nuchal rigidity. Cerebrospinal fluid (CSF) samples indicate an elevated white blood cell count with 85% polymorphonuclear leukocytes and a decreased level of glucose. Gram stain of the CSF shows numerous gram-negative encapsulated rods. Empiric therapy is begun. When culture and sensitivity results are available, the causative organism is found to be a β-lactamase–producing strain of Haemophilus influenzae. At this point, the most appropriate therapy for the patient would be a) ampicillin

b) ceftriaxone
c) chloramphenicol
d) clindamycin
e) vancomycin
f) sulfasoxazole

A

c) chloramphenicol Unverified

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5
Q

A 35 year old Indian woman presented with a 6 year history of a hypopigmented patch on her left thigh and tender red bumps on her shins. The physical examination revealed erythematous nodules on anterior aspects of her legs, bilateral madarosis, and multiple nonhealing ulcrous lesion on the upper and lower extremities. The neurologic examination revealed glove and stocking anesthesia. The lepromin test was negative. The histopathologic examination of skin biopsy showed atrophic epidrmia and numerous acid-fast bacilli in globi and within macrophages. What is the best form of therapy of this patient?

A. Rifampin

B. Dapsone

C. Clofazimine

D. Triple Combination therapy

A

D. Triple Combination therapy Unverified

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6
Q

A 43-year-old woman is recovering from major surgery, following discharge from the hospital, in an assisted-care facility. She develops fever, rales, dyspnea, cough, and purulent sputum. Results of a chest radiograph indicate bilateral pulmonary infiltrates. We send blood and sputum sam- ples to the clinical pathology lab for culturing, but now must turn our attention to what we believe is community-acquired pneumonia caused by antibiotic-resistant pneumococci. We want to start empiric antibiotic ther- apy until culture results are available. Which of the following drugs would be best for this initial therapy?

a. Amoxicillin
b. Cefazolin
c. Erythromycin
d. Levofloxacin
e. Penicillin G
f. Vancomycin
g. Aztreonam

A

d. Levofloxacin or another Quinolone analog Unverified

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7
Q

Despite its short elimination half-life, gentamicin may be administered once daily at high dose in the treatment of hospitalized patients with infections caused by aerobic gram-negative rods. Once daily dosing regimens with gentamicin are likely to result in

A. The rapid emergence of resistance

B. A higher incidence of deafness

C. Higher cost

D. Less Nephrotoxicity

E. A decrease in cure rate

A

D. Less Nephrotoxicity Unverified

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8
Q

A patient with degenerative joint disease is to undergo insertion of a hip prosthesis. To avoid com- plications due to postoperative infection, the surgeon will pretreat this patient with an antibiotic. This hospi- tal has a significant problem with methicillin-resistant Staphylococcus aureus. Which of the following antibi- otics should the surgeon select?

A. Ampicillin

B. Imipenem/cilastatin

C. Gentamicin/piperacillin

D. Vancomycin

E. Cefazolin

A

D. Vancomycin Unverified

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9
Q

A seventy-year-old alcoholic male with poor dental hygiene is to have his remaining teeth extracted for subsequent dentures. He has mitral valve stenosis with mild cardiac insufficiency and is being treated with captopril, digoxin, and furosemide. The dentist decides that his medical history warrants prophylactic antibiotic therapy prior to the procedure and pre- scribes which of the following drugs?

A. Vancomycin

B. Amoxicillin

C. Tetracycline

D. Cotrimoxazole

E. Imipenem

A

B. Amoxicillin

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10
Q

A 33 y/o man has dysuria, meatla erythema and pain, and a purulent urethral discharge. Gram stain of the urethral exudate shows intracellular gram negative diplococci. The medical records indicate that the patient recently had a severe type 1 allergic reaction to penicillin. The most appropriate therapy for this patient would be

A. Ceftriaxone

B. Metronidazole

C. Gentamicin

D. Vancomycin

E. Ciprofloxacin

A

E. Ciprofloxacin

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11
Q

A patient presents to the emergency room with a progressive fever, cough, and general malaise. History determines that he works with sheep on a farm and had just been involved in wool harvesting. Which of the following antibiotics is most appropriate as part of your immediate treatment?

A. Vancomycin

B. Ceftazidne

C. Penicillin

D. Streptomycin

E. Ceftriaxone

A

C. Penicillin

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12
Q

A 29 y/o man who has AIDS and is on retroviral therapy reports for a regular check up and complains of headaches and difficulty with eye-hand coordination. He is found to have cerebral toxoplasmosis. Which of the following drugs is most appropriate for treating this patient?

A. Pyrimethamine plus Sulfadiazine

B. Fluconazole

C. Rifabutin

D. Azithromycin

E. Clofazamine plus Sulfamethoxazole

A

A. Pyrimethamine plus Sulfadiazine

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13
Q

A 21 y/o man was seen in a clinic with a complain of dysuria and urethral discharge of yellow pus. He had a painless clean-based ulcer on the penis and contender enlargement of the regional lymph nodes. Gram stain of the urethral exudate showed gram negative diplococci with polymorphonucleocytes. The patient informed the clinic staff that he was unemployed and had not eaten a meal for 2 days. Immunofluorescent microscopic examination of fluid express ed from the pencil chancre of this patient revealed treponemes. Because he appears to be infected with Treponema palladium, the best course of action would be to

A.Give a single oral dose of fosfomycin

B. Treat with vancomycin

C. Give no other antibiotics because drug treatment of gonorrhea provides coverage for incubating sympathies

D. Treat with oral tetracycline for 7 day

E. Inject Intramuscular benzathine penicillin G

A

E. Inject IM benzathine penicillin G Verified by Ashley

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14
Q

A patient with a gunshot would to the abdomen, which has resulted in spillage of intestinal contents, is brought to the emergency room. Which antibiotic would you select to effectively treat an infection due to Bacteroides fragilis?

A. Aztreonam

B. Clindamycin

C. Gentamicin

D. Azithromycin

E. Doxycycline

A

B. Clindamycin

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15
Q

A 31 y/o woman with a very light complexion visits her PCP because she has a severe sunburn. Examination shows first degree burns over all of the exposed surfaces of her body and some second degree burns on her extremities. She is taking multiple medications for several health issues. She says that she has not been sunbathing or had any unusual exposure to sunshine. Which of the following drugs is most likely to have causes this patients photosensitivity reaction.

A. Acetaminophen

B. Alprazolam

C. Amoxicillin plus clavulanic acid

D. Sulfamethoxazole plus Trimethoprim

E. Erythromycin

A

D.Sulfamethoxazole plus Trimethoprim

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16
Q

A 66 y/o man suffering from COPD was diagnosed with nocardiosis which does not respond to trimethoprim. This is due to Nocardia asteroids that contains a new drug-insensitive enzyme. Which of the following represents this drug insensitive enzyme?

A. Dihydrofolate reductase

B. Superoxide dismutase

C. DNA gyrase

D. Permease

E. Muraminidase

A

A. Dihydrofolate reductase Trimethoprim and Pyrimethamine inhibit Dihydrofolate Reductase. DOC for Nocardial Infections is Sulfonamides Verified by Ashley

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17
Q

A 28 y/o heroin addict is admitted to the hospital with SOB, fever, and night sweats. He has a diastolic blowing murmur in the right second intercostal space and a white blood cell count of 25,000/mm3. Blood cultures are positive for penicillin G resistant, methicillin-sensitive, coagulase positive cocci. The most appropriate treatment for this patient is

A. Nafcillin

B. Aztreonam

C. Ampicillin

D. Isoniazid

E. Piperacillin

A

A. Nafcillin Because the blood culture is methicillin sensitive

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18
Q

You see an 18 y/o obstetric patient late in her 3rd trimester of pregnancy for mild dysuria and urinary urgency. Microscopic examination of the urinary sediment is notable for bacteria and you make a presumptive diagnosis of cystitis. Which one of the following antibiotics would be CONTRAINDICATED? A. Amoxicillin

B. Cephalexin

C. Amoxicillin/clavulanate

D. Nitrofurantoin

E. Trimethoprim/sulfamethoxazole

A

E. Trimethoprim/sulfamethoxazole Sulfonamides are absolutely CI in pregnancy especially in third trimester because they have ability to bind to plasma protiens so sulfonamides can displace the bilirubin from the plasma binding site and increase the free bilirubin in infate- hyperbilirubin in the neonate= KERNICTERUS Verified by Ashley

19
Q

A 60 y/o man develops sepsis after undergoing choledocholithotomy and choledochoduodenostomy. Therapy appropriate for a mixed aerobic and gram-negative infection is insinuated. The patient then experiences several side effects, included muscular weakness, dysphagia, dysarthria, ataxia, and vertigo. Which of drug was most likely used to treat the mixed infection?

A. Streptomycin

B. Aztreonam

C. Piperacillin

D. Ceftriaxone

E. Metronidazole

A

A. Streptomycin D/T the Nm blocking effect of Aminoglycosides

20
Q

A 60 y/o woman with hepatitis C and cirrhosis presents with distended and diffusely tender abdomen. Examination reveals positive fluid waves. Diagnostic paracentesis is performed, which reveals serum ascites albumin gradient > 1.1 g/dL and ascitic fluid polymorphonuclear PMN count of 500/mm. Culture of the fluid yields alpha hemolytic colonies on blood agar. The isolate is bile-solute and penicillin resistant. The patient is started on IV pharmacotherapy. The most likley pharmacotherapeutic agent works by inhibiting:

A. Protein synthesis at the 30 S ribosomal subunit by blocking the binding of aminoacyl tRNA

B. DNA gyrase and topoisomerase IV

C. Peptidoglycan synthesis and assembly

D. DNA dependent RNA polymerase

E. Protein synthesis at the 50S ribosomal subunit by interfering with elongation of the protein by peptidyl transferase

A

Peptidoglycan Synthesis and Assembly

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21
Q

A 3 y/o girl who has missed several scheduled immunizations presents to the emergency room with a high fever. She is irritable and has a stiff neck. Fluid from a spinal tap reveals 20,000 WBC per mL with 85% polymorphonuclear cells. Which of the following is the preferred 3rd generation cephalosporin with good activity agains organisms of childhood menignitis?

A. Ceftazidine

B. Ceftriaxone

C. Penicillin

D. Streptomycin

E. Vancomycin

A

B. Cefriaxone

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22
Q

A patient with TB develops bright-orange red urine and calls his physician in a panic because he is afraid he is bleeding into the urine. The patient has no other urinary tract symptoms. Which of the following medications is most likely to produce this side effect?

A. Streptomycin

B. Isoniazid

C. Pyridoxine

D. Ethambutol

E. Rifampin

A

E. Rifampin

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23
Q

A pregnant woman was hospitalized and catherized with a foley catheter. She developed a urinary tract infection casued by Pseduomonas Aeruginosa and was treated with gentamicin. Which of the following adverse effects was a risk to the fetus when the woman was on gentamicin?

A. Skeletal deformity

B. Hearing loss

C. Mental Retardation

D. Blindness

E. Teratogenesis

A

B. Hearing loss

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24
Q

An elderly diabetic patient is admitted to the hospital with pneumonia. The sputum culture stains for a gram-negative rod. The patient is started on intravenous ampicillin. Two days later, the patient is not improving, and the microbiology lab reports the organism to be a beta lactamase producting H. influenzae. What course of treatment is indicated?

A. Continue with the intravenous ampicillin

B. Switch to intravenous cefotaxime

C. Switch to oral vancomycin

D. Add chloramphenicol

E. No treatment required

A

B. Switch too intravenous cefotaxime

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25
Q

AN 82 y/o patient hospitalized with creatinine clearance of 25 ml/min has a microbial infection requiring treatment with antibiotics. Which one of the following drugs is leasly liley to require a dose adjustment either a small dose than usual or an increased interval between doses?

A. Vancomycin

B. Amphotericin B

C. Erythromycin

D. Imipenem-Cilastatin

E. Gentamicin

A

C. Erythromycin

26
Q

A patient presents to the ER with vomiting, diarrhea, high fever, and delirium. Upon PE you notice large painful buboes, and disseminated intravascular coagulation. Lab diagnosis of aspirate taken from the bubo reveals a gram - neg rod with bipolar staining resembling a safety pin. WHich of the following antibiotics is most approptriate as part of your immediate treatment?

A. Vancomycin

B. Ceftriaxone

C. Penicillin

D. Ceftazidine

E. Streptomycin

A

E. Streptomycin

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27
Q

A 49 year old woman with severe febrile neutropenia had a multi microorganism septicemia including gram + and gram negative aerobes and anaerobes. She was treated with Imipenem plus a drug that inhibits the inactivation of Impipenem by th ehost which of the following drugs is formulated with Imipenem to inhibit its inactivation by the host?

A. Cilastatin

B. Sulbactam

C. Clavulanate

D. Probenecid

E. Trimethoprim

A

A. Cilastatin

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28
Q

A family routinely consumed unpasteurized milk, claiming “better taste” Several members experienced a sudden onset of crampy abdominal pain, fever, and bloody, profuse diarrhea. Campylobacter jejuni was isolated and identified from all patients. Which of the following is the treatmtne of choice for this type of enterocolitis?

A. Ciprofloxacin

B. Campylobacter antitoxin

C. Pepto-Bismol

D. Ampicillin

E. Erythromycin

A

E. Erythromycin

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29
Q

In community acquired pneumonia, pathogens responsible for infeciton include pneumococci, gram negative rods and atypicals sucha s M. pneumonae and C. pneumoniae. Which of the following drugs used as monotherapy is most likely ot be both effective and safe if your patient is pregant?

A. Amoxicillin

B. Azithromycin

C. Ofloxacin

D. Clarithromycin

E. Erthromycin Estolate

A

B. Azithromycin

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30
Q

A 7 year old child presents with pharyngitis and fever of 2 days duration, and microbiology reveals small, translucent beta hemolytic colonies sensitive in vetro to bacitracin. Past history includes a severe allergic reactin to amoxicillin when used for an ear infection. you need to treat this infection, but you prefer not to use a drug that needs parenteral administration. Which of the following agents is most likley to be appropriate in terms of both effecitiveness and saftey?

A. Penicillin G

B. Vancomycin

C. Doxycycline

D. Azithromycin

E. Cefaclor

A

D. Azithromycin

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